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*To*: DML <dinosaur@usc.edu>*Subject*: Re: Dinosaur temperature paper*From*: David Marjanovic <david.marjanovic@gmx.at>*Date*: Mon, 17 Jul 2006 20:02:08 +0200*References*: <5D664573-5F53-4090-A091-714D255D1A72@blueoakfarm.com>*Reply-to*: david.marjanovic@gmx.at*Sender*: owner-DINOSAUR@usc.edu

Interesting...

G is maximum growth rate; g0 is a constant; M is body mass, and the exponent 0.75 is found in a lot of theoretical physiology; T is temperature, and as in many heat systems, e to the exponent kT is often seen. In this case, k is 0.1.

The calculation of g0 and the use of 0.75 are quite well explained. Physicists generally seem to like to express everything as exponents of e.

For example, the body temperature of an Apatosaurus would increase by more than 20°C during ontogeny. This is physiologically and biochemically outrageous. Many biochemical molecules are strongly temperature-dependent,

Indeed so! I should have noticed. Even if we rule out death by chill ( = if we assume poikilothermy and temperatures above 0 °C or some antifreeze adaptation), a change of 20 °C is a lot. Put a snake in the freezer ( = chill it from, say, 25 ° to 5 °), and it will survive without problems, but it will stop moving. Put it in the microwave, and... no, don't.

and it is vanishingly unlikely that a growing Apatosaurus could overhaul its basic biochemistry within a few years.

_Evidence For Triple or Multiple Genome Size in Sauropods_ ;-)

I wonder what happens in adults that have reached their final adult size (and thus have a growth rate close to zero. Using the same logic and the same equation that Gillooly et al. use to “calculate” temperature during ontogeny, I calculate that the body temperature of an adult Apatosaurus is close to zero [Kelvin].

Not quite.

T = 10 log [G (M exp -0.75)/g0]

If G is 0, we get T = 10 log 0 = 10 x 1 = 10. Right? Ten kelvin! WooHoo!!!

And what about the review process? Is this a case of “Publish them all, and let God sort them out!”?

Well said! I don't see who else will sort it out over (at least) the next 5 years. News all over the world seem to have accepted the published results as truth.

**Follow-Ups**:**Re: Dinosaur temperature paper***From:*David Marjanovic <david.marjanovic@gmx.at>

**References**:**Dinosaur temperature paper***From:*Richard Cowen <cowen@blueoakfarm.com>

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